Portable devices having multiple power interfaces

ABSTRACT

Portable devices having multiple power interfaces are described herein. According to one embodiment of the invention, a portable electronic device includes, but is not limited to, a processor, a memory coupled to the processor for storing instructions, when executed from the memory, cause the processor to perform one or more functions, a battery coupled to provide power to the processor and the memory, and a battery charging manager coupled to charge the battery using power derived from a plurality of power sources including a solar power source. Other methods and apparatuses are also described.

FIELD OF THE INVENTION

The present invention relates generally to portable electronic devices.More particularly, this invention relates to portable electronic deviceshaving multiple power interfaces.

BACKGROUND

Handheld computing devices typically use standard battery chemistriesincluding ni-cad, lithium-ion, and nickel-metal hydride. In order torecharge these batteries, operators may use standard recharging optionssuch as, for example, conventional AC (alternating current) outlets.However, mobile users who are in remote locations oftentimes do not haveaccess to conventional AC outlets. As a result, they oftentimes have noway of recharging the batteries of their handheld computing devices.

Recently, solar power has been used to power up a handheld device. Asdemands for the power of the handheld computing devices increase, itbecomes more important to provide stable power to the devices. However,given the characteristics of the solar cells that provide solar power,it is relatively difficult to track the solar power drawn from the solarcells to maintain relatively stable solar power output.

FIG. 1A is a diagram illustrating a model circuit of a typical solarcell. As shown in FIG. 1A, the I-V equation for the diode part of themodel can be written as follows:

$I_{D} = {I_{o}{\mathbb{e}}^{\frac{{qV}_{CELL}}{mkT}}}$The I-V curve for the cell may be described as follows:

$\begin{matrix}{I_{CELL} = {I_{Q} - {I_{o}{\mathbb{e}}^{\frac{{qV}_{CELL}}{kT}}}}} & \lbrack 1\rbrack\end{matrix}$Similarly, the V-I curve may be described as follows:

$V_{CELL} = {\frac{kT}{q}\left( {{\ln\left( {I_{Q} - I_{CELL}} \right)} - {\ln\left( I_{0} \right)}} \right)}$

For a typical cell the Cell current is about 1 Amp at 650 mV so I₀ canbe computed to be 1.389×10⁻¹¹. FIG. 1B is a diagram illustrating anexample of the V-I characteristic of a solar cell. The output is similarto a current limited voltage source. The power out of the cell at anygiven point on the V-I curve is the voltage times the current. FIG. 1Balso includes a plot of the available cell power plotted as a functionof voltage. As shown in FIG. 1B, there is a fairly sharp peak operatingpower that is the desired operating point for maximum power out.

FIG. 2A is a schematic diagram illustrating a typical solar power systemusing a boost switching regulator and a storage battery. Referring toFIG. 2A, the boost regulator would be used in low cell count systemswhere the battery voltage is larger than the available cell voltage. Theboost regulator boosts the solar cell voltage to a voltage suitable fora conventional battery charger. A controller monitors the current intothe battery charger and controls the current drawn by the charger tocontrol the power draw from the solar cell. Since the output voltage isconstant the power to the battery charger is proportional to the currentdrawn so the control be considered to be a power control and the solarcell sees the converter as a adjustable constant power load asillustrated in FIG. 2B.

FIG. 3A is a diagram illustrating a cell V-I source plot with a resistorload line and some constant power load lines. Referring to FIG. 3A, theresistor load is always stable since both the source and loadresistances are positive. The constant power loads are conditionallystable. The 600 mW load is always unstable because there is no interceptwith the cell V-I curve. The 400 mW and 500 mW loads are stable at theIntercept B locations because the positive conductance of the cell isgreater than the negative conductance of the load. These loads areunstable at Intercept A. With the 600 mW load the load will continue todemand current that the cell cannot supply so the cell will go intoconstant current mode and the cell voltage will go down. This similarsituation will apply to the other two loads if cell voltage is belowIntercept A; however, if the cell voltage is above Intercept A, the cellvoltage will increase and finally settle at Intercept B.

FIG. 3B is a diagram illustrating a SPICE simulation result that showsthe behavior of the system when the load current is stepped up in 0.5 mAsteps from a load current of about 75 mA. At each step the cell voltagedrops by an increasing amount and when the peak power point is exceededso there is no intercept, the system collapses. The controller in FIG.2A must sense the impeding collapse and recover before the actualcollapse occurs.

In addition, a conventional portable device or handheld device typicallyincludes a battery and an AC adaptor for charging the battery. Certainhandheld devices, such as a calculator, include a solar panel togenerate solar power to activate the device. However, such a device doesnot normally include other power sources to charge the battery.Sometimes the solar power source or AC outlet may not be convenientlyavailable. In such circumstances, a device limited to one chargingmethod may not function properly.

SUMMARY OF THE DESCRIPTION

Techniques for operating devices with solar power are described herein.In one aspect of the invention, apparatus for operating a portableelectronic device with solar power includes, but is not limited to, avoltage converter and a controller coupled to the voltage converter. Thevoltage converter includes an input capable of being coupled to a solarpower source and an output capable of being coupled to an electronicload, such as, for example, a portable electronic device. The voltageconverter is configured to monitor or detect an amount of power drawn bythe electronic load at the output of the voltage converter. In responseto the monitored power drawn, the controller is configured to controlthe voltage converter to adjust further output power provided to theelectronic load. As a result, the output voltage from the solar powersource is maintained within a predetermined range.

According to another aspect of the invention, a portable electronicdevice includes, but is not limited to, a processor, a memory coupled tothe processor for storing instructions, when executed from the memory,cause the processor to perform one or more functions, a battery coupledto provide power to the processor and the memory, and a battery chargingmanager coupled to charge the battery using power derived from aplurality of power sources including a solar power source.

Other features of the present invention will be apparent from theaccompanying drawings and from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings in which likereferences indicate similar elements.

FIG. 1A is a diagram illustrating a model circuit of a typical solarcell.

FIG. 1B is a diagram illustrating characteristics of a typical solarcell as shown in FIG. 1A.

FIG. 2A is a schematic diagram of a conventional solar power circuit.

FIG. 2B is a schematic diagram of a module for a conventional solarpower circuit as shown in FIG. 2A.

FIGS. 3A-3B are diagrams illustrating certain characteristics ofcircuits as shown in FIGS. 2A-2B.

FIGS. 4A-4B are schematic diagrams illustrating systems for operating anelectronic device with solar power according to certain embodiments ofthe invention.

FIGS. 5A-5B are diagrams illustrating certain characteristics ofcircuits as shown in FIGS. 4A-4B.

FIG. 6 is a schematic diagram illustrating a system for operating anelectronic device with solar power according to an alternativeembodiment of the invention.

FIG. 7 is a flow diagram illustrating a process for operating anelectronic device with solar power according to one embodiment of theinvention.

FIGS. 8A-8D are block diagrams illustrating examples of portableelectronic devices having a power interface for various power sources,according to certain embodiments of the invention.

FIG. 9 is a flow diagram illustrating an example of a process forinterfacing a portable device with a variety of power sources accordingto one embodiment of the invention.

FIG. 10 is a block diagram of a digital processing system, which may beused with one embodiment of the invention.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to providea more thorough explanation of embodiments of the present invention. Itwill be apparent, however, to one skilled in the art, that embodimentsof the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form, rather than in detail, in order to avoidobscuring embodiments of the present invention.

Reference in the specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the invention. The appearances of the phrase “in one embodiment” invarious places in the specification do not necessarily all refer to thesame embodiment.

Techniques for Operating Devices with Solar Power

According to certain embodiments of the invention, an amount of powerdrawn at the point of a load of solar power is monitored and themonitored power is used to control a voltage converter that providesregulated power. For example, contrary to conventional approaches wherethe voltage of an output of a solar power source is monitored and usedto control a charger to consume the solar power, the amount of power(e.g., an amount of current or voltage into a load with knowncharacteristics) being drawn is monitored at an input of an electronicload, such as, for example, a battery or a battery charger that utilizesthe solar power to charge and/or recharge the battery is monitored.Based on the monitored power drawn, a controller (e.g., a programmablemicrocontroller) is invoked to determine statuses of the solar powersources and to generate a control signal using a predeterminedalgorithm, in response to the monitored power being drawn by theelectronic load. The control signal is used to control the voltageconverter to adjust further amount of power to be drawn by theelectronic load. The above operations may be performed via hardware,software, or a combination of both.

FIG. 4A is a block diagram illustrating an example of an apparatus foroperating an electronic device with solar power according to oneembodiment of the invention. In one embodiment, the apparatus includes,but is not limited to, a voltage converter and a controller coupled tothe voltage converter. The voltage converter includes an input capableof being coupled to a solar power source and an output capable of beingcoupled to an electronic load, such as, for example, a portableelectronic device. The voltage converter is configured to monitor ordetect an amount of power drawn by the electronic load at the output ofthe voltage converter. In response to the monitored power drawn, thecontroller is configured to control the voltage converter to adjust anamount of power to be drawn subsequently. As a result, the outputvoltage from the solar power source is maintained within a predeterminedrange.

Referring to FIG. 4A, exemplary circuit 400 includes a voltage converter402 and a controller 404 coupled to voltage converter 402. An input ofthe voltage converter 402 is capable of being coupled to a solar powersource 401, which may include one or more solar cells, or solar cellarrays. The solar power source 401 is configured to absorb energy fromthe light such as sun light and transform the absorbed energy intoelectricity. The voltage converter 402 is configured to convert theelectricity from the solar power source 401 into proper form of electricpower that is suitable to be used by the electronic load 403.

In addition, a controller 404 is coupled to a node 406 coupling an inputof the electronic load 403 and an output of the voltage converter 402.Specifically, controller 404 is configured to monitor an amount of powerbeing drawn from the output of the voltage converter by the electronicload 403. For example, the controller 404 may be configured to monitoran amount of current being drawn by the electronic load 403, forexample, using a current sense resistor (not shown). Alternatively, thecontroller 404 may be configured to monitor the voltage of node 406coupling the electronic load 403 and the voltage converter 402, or acombination of both voltage and current being drawn at node 406.

In response to the monitored power being drawn, according to oneembodiment, the controller 404 determines the statuses of solar powersource 401. For example, based on the monitored power being drawn atnode 306, the controller 404 is able to determine whether the maximumpower that the solar power source 401 can generate has been reached,given the characteristic of the solar power source 401, such as, forexample, characteristics similar to those shown in FIGS. 1A and 1B.Alternatively, in response to the monitored power being drawn, thecontroller 404 determines whether an output voltage of the solar powersource 401 has dropped below a predetermined threshold in view ofcertain characteristics of solar power source 401.

Based on the determined statuses of the solar power source 401,according to one embodiment, the controller 404 is configured togenerate a control signal to control the voltage converter 402. Inresponse to the control signal received from the controller 404, thevoltage converter 402 is configured to adjust a subsequent amount ofpower to be drawn by the electronic load 403, such that the output ofthe solar power source 401 may be maintained within a predeterminedrange.

In one embodiment, the controller 404 is a programmable controller thatmay be programmed to perform the determination described above based ona predetermined algorithm. For example, controller 404 may include amachine-readable storage medium (not shown) to store one or more machineinstructions. In response to the monitored power being drawn, thecontroller 404 is configured to execute the one or more machineinstructions stored therein to determine the status of the solar powersource 401. The one or more machine instructions may include one or moreexecutable routines, which may be programmed and stored in themachine-readable storage medium of controller 406. The one or moreroutines may be used to generate the control signal based on themonitored power being drawn using a predetermined relationship betweenthe monitored power and one or more characteristics of the solar powersource 401, such as, for example, a diagram as shown in FIGS. 5A and 5Baccording to certain embodiments of the invention.

In one embodiment, the solar power source 401 may be integrated with theexemplary circuit 400. Alternatively, the solar power source 401 may beimplemented external to the exemplary circuit 400 and is capable ofbeing interfaced with the exemplary circuit 400. Note that solar powersource 401 is used herein as an example for the purposes of illustrationonly. Other types of power sources may also be applied.

The electronic load 403 may include, but is not limited to, a portableelectronic device, such as, for example, a notebook/laptop computer, amedia player (e.g., MP3 or video player), a cellular phone, a personaldigital assistant (PDA), an image processing device (e.g., a digitalcamera or video recorder), and/or any other handheld computing devices,or a combination of any of these devices. The electronic load 403 mayfurther include a battery and/or a battery charger to charge or rechargethe battery using the electric power generated/converted from the solarpower source 401.

Similarly, according to one embodiment, electronic load 403 may beintegrated with circuit 400. Alternatively, electronic load 403 may beimplemented external to circuit 300 and is capable of being interfacedwith the exemplary circuit 400, such as, for example, via a dedicatedpower interface or via a shared communication interface (e.g., networkinterface, etc.) Other configurations may exist.

FIG. 4B is a simplified schematic diagram illustrating an apparatus forcharging a battery from a solar cell, according to one embodiment of theinvention. For example, exemplary circuit 450 may be implemented as anembodiment of circuit 400 of FIG. 4A.

According to one embodiment, similar to circuit 400 of FIG. 4A,exemplary circuit 450 includes, but is not limited to, a voltageconverter 452 having an input coupled to a solar power source, such as,for example, solar cell or cells 451. The voltage converter 452 includesan output coupled to an electronic load 453, which may include abattery, battery charger, and/or a portable electronic device asdescribed above. In one embodiment, voltage converter 452 includes, butis not limited to, a power switching device, in this example, havingswitches 456-457, and a switching regulator 455 (in this example, apulse width modulator or PWM) to control a switching duty cycle of thepower switching device (e.g., switches 456-457). Note that a switchingdevice may be a FET (field effect transistor) or a bipolar transistor,etc. Since the PWM 455 can be implemented by digital logic or aprogrammed process then the PWM 455 can be contained in the controller454.

In addition, voltage converter 452 further includes an energy storagedevice, in this example, an inductor 458, to store energy during aswitching duty cycle. Further, exemplary circuit 450 may further includeanother energy storage device, in this example, a capacitor 459, totemporarily store energy derived from the solar power source 451,particularly, during an initialization phase of the voltage converter452.

Furthermore, exemplary circuit 450 further includes an output powersensing circuit to sense the power being drawn by the electronic load453. The sensing circuit may include a current sensing device and/orvoltage sensing device. In this example, the sensing circuit includes acurrent sensing resistor 461 and a current sensor 460. The currentsensing resistor 461 is coupled in series between an output of thevoltage converter 452 and an input of the electronic load 453.Typically, current sensing resistor 461 is a relatively high precisionresistor, where an amount of current flowing through the resistor 461can be measured by measuring a voltage drop across the current sensingresistor 461, for example, by current sensor 460. Since the load is abattery the voltage of the load is constant so the power is proportionalto the current. The change in power can then be used to determine thatthe maximum power available from the solar cell is being transferred tothe load.

An output of the current sensor 460 may be input to controller 454 viapath 462, where the controller 454 may generate a control signal basedon the input received from current sensor 460. Controller 454 may beprogrammable controller (e.g., FPGA) having a machine storage medium(e.g., EEPROMs or electrically erasable programmable read-only memories,etc.) therein for storing instructions, which when executed from themachine storage medium, cause the controller to perform certainoperations, including at least generating the control signal based onthe current sensing information received from the current sensor 460.The operations may be implemented using a predetermined algorithm and/oraccording to certain information or condition stored in a lookup tablewithin the controller.

Note that the specific algorithm employed by the programmableinstructions may be tailored to or based on a specific operatingenvironment and/or characteristics of the electronic load 453. Thecontrol signal generated from the controller 454 may be used by PWM 455to adjust further switching duty cycles of the power switching device(e.g., switches 456 and/or 457). Optionally, output voltage may also bemonitored and input to controller 454 via path 463, for example, toprevent a battery overcharged. Note that in this example, circuit doesnot have to include a battery charger although one could be added or thecontroller 454 could be programmed to manage the charging.

In a particular embodiment, switch 456 may be an n-channel MOSFET (NMOS)and switch 457 may be a p-channel MOSFET (PMOS). The NMOS and PMOS FETsact as switches that are activated by a pulse width modulator 455 suchthat when one switch is on, the other is off. A capacitor 459 holds thecell voltage during the brief switching times so that the cell currentI_(CELL) is essentially constant. The inductor 458 is used as the energystorage element for the voltage converter (e.g., a booster converter)created by the switches 456 and/or 457. The output of the switches isconnected to the electronic load (e.g., a battery) through a relativelysmall sense resistor R_(SENSE) 461 that is used with a current sensecircuit 460 to the controller 454 which may be a digital control circuitwith A/D converters for the current sense and/or to monitor the batteryvoltage V_(BAT). The V_(BAT) monitor may be needed if there is a risk ofbattery overcharging. The controller 454 then generates the pulse widthmodulation timing for PWM 455. Note that exemplary circuit 450 is shownfor the illustration purposes only. More or fewer components may beutilized and other configurations may also be implemented. In aparticular embodiment, switching devices 456-457 may be an IRF6623compatible power MOSFET (metal-oxide semiconductor FET), which isavailable from International Rectifier

FIG. 5A is a diagram illustrating a timeline for the voltage across theinductor and the current through the inductor, according to oneembodiment of the invention. As shown in FIG. 5A, it is assumed thatthere is some significant average current I_(AVE) that is larger thanthe incremental current change ΔI. Referring to FIG. 5A, when the NMOSFET (e.g., switch 456 of FIG. 4B) is on (during T₂), then voltage acrossinductor L (e.g., inductor 458 of FIG. 4B) is V_(CELL) (ignoring switchdrop) so that the current may increase approximately by:

${\Delta\; I_{F}} = \frac{V_{CELL} \cdot T_{2}}{L}$When the PMOS FET (e.g., switch 457 of FIG. 4B) is on (during T₁), thenthe voltage across inductor L (e.g., inductor 458 of FIG. 4B) isV_(BAT)−V_(CELL) and the current change during this time isapproximately:

${\Delta\; I_{R}} = {\frac{\left( {V_{BAT} - V_{CELL}} \right) \cdot T_{1}}{L} = {\frac{V_{BAT} \cdot T_{1}}{L} - \frac{V_{CELL} \cdot T_{1}}{L}}}$For steady state operation where I_(AVE) is constant, then

$\begin{matrix}{{{\Delta\; I_{F}} = {\Delta\; I_{R}}}{\frac{V_{CELL} \cdot T_{2}}{L} = {\frac{V_{BAT} \cdot T_{1}}{L} - \frac{T_{CELL} \cdot T_{1}}{L}}}{{\frac{V_{CELL} \cdot T_{2}}{L} + \frac{V_{CELL} \cdot T_{1}}{L}} = \frac{V_{BAT} \cdot T_{1}}{L}}{{V_{CELL} \cdot T_{P}} = {V_{BAT} \cdot T_{1}}}{V_{CELL} = \frac{V_{BAT} \cdot T_{1}}{T_{P}}}} & \lbrack 2\rbrack\end{matrix}$Equation [2] states that the current will be drawn from the solar cellto satisfy the condition of FIG. 1B. This means that from Equation [1]:

$I_{AVE} = {I_{CELL} = {I_{Q} - {I_{o}{\mathbb{e}}^{\frac{{qV}_{CELL}}{kT}}}}}$

The result is illustrated in FIG. 5B. The pulse width modulation willset a voltage operating point on the current and power curves. This isnow unconditionally stable and the power peak can be found withoutstability concerns.

A significant advantage of this approach is that it is more efficientthan the approach of FIG. 2A, because in FIG. 2A the output voltageV_(T) must always be higher than the maximum battery voltage and thereis a power loss in the charger due to the voltage difference that willnot exist in the new solution since the current goes directly into thebattery. Note that any appropriate power device could be used for theswitching device. For example, according to one embodiment, it is alsopossible for the PMOS switch to be replaced with a Schottky diode asshown in FIG. 6.

FIG. 7 is a flow diagram illustrating an example of a process foroperating a portable device with solar power according to one embodimentof the invention. Exemplary process 700 may be performed by a processinglogic that may include hardware (circuitry, dedicated logic, etc.),software (such as is run on a dedicated machine), or a combination ofboth. For example, process 700 may be performed by systems as shown inthe above figures.

In one embodiment, process 700 includes, but is not limited to,generating regulated power via a voltage converter to power a portableelectronic device based on solar power derived from a solar powersource, monitoring power drawn at an output of the voltage converter bythe portable electronic device, and in response to the monitored power,controlling the voltage converter to adjust further regulated power tothe portable electronic device.

Referring to FIG. 7, at block 701, in response to an output voltage froma solar power source (e.g., a solar cell or an array of solar cells), avoltage converter (e.g., a booster converter) is configured to provide aregulated power to an electronic load (e.g., a portable electronicdevice, a battery, and/or a battery charger). At block 702, an amount ofpower (e.g., current and/or voltage into a load with knowncharacteristics) drawn at the output of the voltage converter by theelectronic load is monitored, for example, using a current sense device.At block 703, in response to the monitored power, adjusting (e.g., usinga programmable controller) the regulation (e.g., controlling a pulsewidth modulator of the voltage converter) of the power further to beprovided to the electronic load. Other operations may also be performed.

As a result, with some or all of the solar power tracking techniques,the output of the solar power source can be maintained within aconsistent range and chances of a sharp drop of voltage or power outputfrom the solar power source due to being overdrawn can be eliminated, inorder to provide power to an electronic load with relatively highstability. Again, solar cells or solar cell arrays are used as examplesfor the purposes of illustration only. It will be appreciated that othertypes of power sources may also be applied.

Smart Power Interfaces

As described above, a conventional portable device typically use an ACadaptor to charge a battery of the portable device. Alternatively, aconventional portable device such as calculator utilizes a solar panelto directly power up the device. A conventional portable device lacks aflexible and smart power interface that can provide power to theportable device from multiple different power sources, including anAC/DC power and solar power sources.

According to one embodiment, a portable electronic device includes apower interface that can provide power to the portable electronic devicefrom a variety of different power sources based on the operatingcircumstances of the portable electronic device. According to certainembodiments of the invention, a portable electronic device may drawpower from a traditional AC/DC power, solar power, power from a varietyof communication lines (such as, for example, a network connection(e.g., Ethernet), a USB (universal serial bus) connection, or an IEEE1394 compatible connection, also referred to as Firewire), a telephoneline, or a combination of any of these power sources.

Any of these power sources may be used to charge or recharge a batteryof a portable electronic device. When a solar power source is utilized,one or more solar power tracking techniques described above may beutilized, for example, as a part of power management component or abattery charging manager of the portable electronic device. A batterycharging manager of a portable electronic device is able to determinethe operating environment of the portable electronic device and theavailability of the various power sources. In response, the batterycharging manager may select one or more of the power sources that areappropriate under the circumstances to be used to charge a battery ofthe portable electronic device.

In one embodiment, a portable electronic device, which can draw powerfrom a variety of power sources, may be a notebook/laptop computer, amedia player (e.g., an MP3 or video player), a cellular phone, apersonal digital assistant (PDA), an image processing device (e.g., adigital camera or video recorder), and/or any other handheld computingdevices, or a combination of any of these devices (e.g., a combodevice).

FIGS. 8A-8D are block diagrams illustrating examples of portableelectronic devices having a power interface for various power sources,according to certain embodiments of the invention. In one embodiment, aportable electronic device includes, but is not limited to, a processor,a memory coupled to the processor for storing instructions, whenexecuted from the memory, which cause the processor to perform one ormore functions, a battery coupled to provide power to the processor andthe memory, and a battery charging manager coupled to charge the batteryusing power derived from a plurality of power sources including a solarpower source.

Referring to FIG. 8A, in this embodiment, portable device 800 includes,a battery charging manager 801 to manage power to be supplied to one ormore system components 803. The system components 803 may include majorcomponents of a portable electronic device mentioned above. When ACpower is available, power manager 801 may draw power directly from theAC power (not shown) to provide power to system components 803.Meanwhile, the power manager 801 may distribute a portion of the ACpower to charge or recharge battery 802. When the AC power is notavailable, the battery charging manager 801 may enable the battery 802to provide power to system components 803 for operations.

In addition, battery charging manager 801 may draw power from a varietyof power sources to charge or recharge battery 802, which in turn may beused to provide power to the system components 803 subsequently orsubstantially concurrently. According to certain embodiments of theinvention, various power sources may include power provided from acommunication line or media, such as, for example, a network connection804 (e.g., Ethernet), a USB (universal serial bus) connection 805, or anIEEE 1394 compatible connection 806, also referred to as Firewire), atelephone line (not shown), or a combination of any of these powersources.

In addition, the battery charging manager 801 may further draw powerfrom a solar power source 809 having one or more solar cells or arrays,via the auxiliary charger 807 and/or controller 808. In one embodiment,the auxiliary charger 807 and controller 808 may be implemented usingsome or all of the techniques described above with respect to FIGS. 3-7.

According to one embodiment, battery charging manager 801 is configuredto determine the statuses of various power sources 805-806 and 809, aswell as other power sources (not shown). Based on the statuses of thepower sources, the battery charging manger 801 may select one or more ofthe power sources, individually or substantially concurrently, to chargethe battery 802.

According to certain embodiments, various external power sources (e.g.,power sources 805-806) may be coupled to the portable device 800 via oneor more power interface circuits. Alternatively, these power sources maybe coupled to the portable device 800 using a shared interface circuitwith data connection (e.g., shared network connector, USB connector,IEEE 1394 connector, or a telephone jack, etc.)

In addition, controller 808 may communicate with one or more systemcomponents 803 to further enhance the solar power charging techniquesbased on the operating environment or statuses of the system components803. Further, portable device 800 may include battery level indicator810 for indicating a current battery level to a user. Otherconfigurations may exist.

FIG. 8B is a block diagram illustrating an example of a portableelectronic device according to an alternative embodiment of theinvention. Unlike the embodiment as shown in FIG. 8A where the solarpower source 809 is integrated within the portable device 800, in thisembodiment, the solar power source 809 is external to the portabledevice 800. The solar power source 809 may be non-fixedly coupled to theauxiliary charger, for example, via an interface (e.g., a connector orsocket). That is, the solar power source 809, which may include a solarpanel having one or more solar cells or arrays, may be plugged into andremoved from the portable device 800, for example, using a cable. Theauxiliary charger 807 and/or controller 808 may further includeplug-n-play capabilities to detect whether the solar power source 809 isinserted and whether it is appropriate to use the power drawn from thesolar power source 809 to charge or recharge the battery 802. In thisembodiment, the solar power source 809 may be manufactured by the samemanufacturer of the portable device 800 or a third party.

FIG. 8C is a block diagram illustrating an example of a portableelectronic device according to another embodiment of the invention.Unlike the embodiments as shown in FIGS. 8A and 8B, where the solarpower source 809 and/or auxiliary charger 807 are integrated within theportable device 800, in this embodiment, the solar power source 809 andauxiliary charger 807 are implemented as a power package 812 external tothe portable device 800. The power package 812 becomes a portable powerpackage that may be plugged into the portable device 800 via aninterface circuit 811, for example, using a cable. Thus, the solar powersource becomes an option to the portable device 800. As a result, thecost of the portable device 800 may further be reduced, since some usersmay not need the solar power option. Similarly, the power package 812may be manufactured by the same manufacturer of the portable device 800or a third party.

FIG. 8D is a block diagram illustrating an example of a portableelectronic device according to another embodiment of the invention. Inthis embodiment, the power package 812 further includes a secondauxiliary charger 807 and an auxiliary battery 813, while the portabledevice 800 maintains a first auxiliary charger 814. The power package812 becomes a portable power package that may be plugged into theportable device 800 via an interface circuit 811, for example, with orwithout a cable.

In this embodiment, the auxiliary battery 813 may be charged by thesecond auxiliary charger 807 using power derived from the auxiliarypower source, in this example, a solar panel having one or more solarcells or arrays. Thus, the auxiliary battery may be charged while thepower package 812 is not coupled to the portable device 800. The chargedauxiliary battery 813 may then be used to charge or recharge the battery802, when the power package 812 is coupled to the portable device 800.Alternatively, when the power package 812 is coupled to the portabledevice 800 (e.g., via a cable), the auxiliary battery 813 may be chargedby the second auxiliary charger 807 using the solar power derived fromthe solar power panel 809, while providing power to charge, viaauxiliary charger 807, battery 802 substantially concurrently. Auxiliarycharger 807 may be implemented with some or all of the solar powertracking techniques described above.

Similar to the embodiment as shown in FIG. 8C, the solar power package812 becomes an option to the portable device 800. As a result, the costof the portable device 800 may further be reduced, since some users maynot need the solar power option. Similarly, the power package 812 may bemanufactured by the same manufacturer of the portable device 800 or athird party.

FIG. 9 is a flow diagram illustrating an example of a process forinterfacing a portable device with a variety of power sources accordingto one embodiment of the invention. Exemplary process 900 may beperformed by a processing logic that may include hardware (circuitry,dedicated logic, etc.), software (such as is run on a dedicatedmachine), or a combination of both. For example, process 900 may beperformed by systems as shown in FIGS. 8A-8D. In one embodiment, process900 includes, but is not limited to, determining statuses of a pluralityof power sources available to the portable electronic device, where theplurality of power sources includes a solar power source, and selectingone of the plurality of power sources to charge a battery of theportable electronic device, including selecting the solar power sourcewhen an operating environment is appropriate.

Referring to FIG. 9, at block 901, multiple power sources (e.g., solarpower, power received from a network connection, USB connection, an IEEE1394 or Firewire connection, or a telephone line, etc.) are provided tocharge a battery of a portable electronic device. At block 902,processing logic determines statuses (e.g., availability) of the variouspower sources. In response to a given operating environment of theportable electronic device, at block 903, processing logic selects atleast one of the multiple power sources that is appropriate under thecircumstances to charge or recharge the battery of the portableelectronic device. Other operations may also be performed.

Data Processing System Examples

FIG. 10 is a block diagram of a digital processing system, which may beused with one embodiment of the invention. For example, the system 1000shown in FIG. 10 may be used as a portable electronic device asdescribed above, which may be, for example, a notebook/laptop computer,a media player (e.g., MP3 or video player), a cellular phone, a personaldigital assistant (PDA), an image processing device (e.g., a digitalcamera or video recorder), and/or any other handheld computing devices,or a combination of any of these devices. Further, system 1000 mayinclude a solar power tracking mechanism and/or a power interface forvarious power sources described above.

Note that while FIG. 10 illustrates various components of a computersystem, it is not intended to represent any particular architecture ormanner of interconnecting the components, as such details are notgermane to the present invention. It will also be appreciated thatnetwork computers, handheld computers, cell phones and other dataprocessing systems which have fewer components or perhaps morecomponents may also be used with the present invention. The computersystem of FIG. 10 may, for example, be an Apple Macintosh computer orPower Book, or an IBM compatible PC.

As shown in FIG. 10, the computer system 1000, which is a form of a dataprocessing system, includes a bus or interconnect 1002 which is coupledto one or more microprocessors 1003 and a ROM 1007, a volatile RAM 1005,and a non-volatile memory 1006. The microprocessor 1003, which may be,for example, a PowerPC G4 or PowerPC G5 microprocessor from Motorola,Inc. or IBM, is coupled to cache memory 1004 as shown in the example ofFIG. 10. The bus 1002 interconnects these various components togetherand also interconnects these components 1003, 1007, 1005, and 1006 to adisplay controller and display device 1008, as well as to input/output(I/O) devices 1010, which may be mice, keyboards, modems, networkinterfaces, printers, and other devices which are well-known in the art.

Typically, the input/output devices 1010 are coupled to the systemthrough input/output controllers 1009. The volatile RAM 1005 istypically implemented as dynamic RAM (DRAM) which requires powercontinuously in order to refresh or maintain the data in the memory. Thenon-volatile memory 1006 is typically a magnetic hard drive, a magneticoptical drive, an optical drive, or a DVD RAM or other type of memorysystem which maintains data even after power is removed from the system.Typically, the non-volatile memory will also be a random access memory,although this is not required.

While FIG. 10 shows that the non-volatile memory is a local devicecoupled directly to the rest of the components in the data processingsystem, the present invention may utilize a non-volatile memory which isremote from the system; such as, a network storage device which iscoupled to the data processing system through a network interface suchas a modem or Ethernet interface. The bus 1002 may include one or morebuses connected to each other through various bridges, controllers,and/or adapters, as is well-known in the art. In one embodiment, the I/Ocontroller 1009 includes a USB (Universal Serial Bus) adapter forcontrolling USB peripherals. Alternatively, I/O controller 1009 mayinclude an IEEE-1394 adapter, also known as FireWire adapter, forcontrolling FireWire devices.

According to certain embodiments of the invention, system 1000 furtherinclude a battery (not shown) which may be charged or recharged by asolar power source (not shown) having one or more solar cells or arrays,which may be integrated with system 1000 or alternatively, external tosystem 1000 using some or more of the techniques described above.Further, the battery of system 1000 may be charged or recharged usingpower derived from a variety of power sources including, but is notlimited to, a network connection (e.g., Ethernet), a USB (universalserial bus) connection, or an IEEE 1394 compatible connection, alsoreferred to as Firewire), a telephone line (not shown), or a combinationof any of these power sources. Other configurations may exist.

Some portions of the preceding detailed descriptions have been presentedin terms of algorithms and symbolic representations of operations ondata bits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities. Usually, though not necessarily,these quantities take the form of electrical or magnetic signals capableof being stored, transferred, combined, compared, and otherwisemanipulated. It has proven convenient at times, principally for reasonsof common usage, to refer to these signals as bits, values, elements,symbols, characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the above discussion, itis appreciated that throughout the description, discussions utilizingterms such as “processing” or “computing” or “calculating” or“determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical(electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

Embodiments of the present invention also relate to an apparatus forperforming the operations herein. This apparatus may be speciallyconstructed for the required purposes, or it may comprise ageneral-purpose computer selectively activated or reconfigured by acomputer program stored in the computer. Such a computer program may bestored in a computer readable storage medium, such as, but is notlimited to, any type of disk including floppy disks, optical disks,CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), randomaccess memories (RAMs), erasable programmable ROMs (EPROMs),electrically erasable programmable ROMs (EEPROMs), magnetic or opticalcards, or any type of media suitable for storing electronicinstructions, and each coupled to a computer system bus.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general-purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct more specializedapparatus to perform the required method operations. The requiredstructure for a variety of these systems will appear from thedescription below. In addition, embodiments of the present invention arenot described with reference to any particular programming language. Itwill be appreciated that a variety of programming languages may be usedto implement the teachings of embodiments of the invention as describedherein.

A machine-readable medium may include any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputer). For example, a machine-readable medium includes read onlymemory (“ROM”); random access memory (“RAM”); magnetic disk storagemedia; optical storage media; flash memory devices; electrical, optical,acoustical or other form of propagated signals (e.g., carrier waves,infrared signals, digital signals, etc.); etc.

In the foregoing specification, embodiments of the invention have beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident that various modifications may be made thereto withoutdeparting from the broader spirit and scope of the invention as setforth in the following claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

1. A solar power package for use with an electronic device, the packagecomprising: at least one solar cell operable to derive solar power fromsolar energy; and a power charger operable to provide the derived solarpower to the portable electronic device, wherein the derived solar poweris provided in a plug-and-play fashion when the portable electronicdevice is coupled to the package, and wherein the power charge isoperative to adjust the amount of power provided to the portableelectronic device based on attributes of the portable electronic device.2. The solar power package of claim 1, wherein the power charger isfurther operable to provide the derived solar power to the portableelectronic device by charging a battery of the portable electronicdevice.
 3. The solar power package of claim 1, further comprising anaccessory battery, wherein: the power charger is further operable tocharge the accessory battery with the derived solar power; and theaccessory battery is operable to provide the derived solar power to theportable electronic device.
 4. The solar power package of claim 1,further comprising an accessory battery and wherein the power charger isfurther operable to concurrently: provide a first portion of the derivedsolar power to the portable electronic device; and charge the accessorybattery with a second portion of the derived solar power.
 5. The solarpower package of claim 1, wherein at least a portion of the at least onesolar cell is removable from the solar power package.
 6. The solar powerpackage of claim 1, wherein the solar power package is capable of beingplugged into and removed from the portable electronic device.
 7. Thesolar power package of claim 1, wherein the power charger is furtheroperable to be enabled to provide the derived solar power to theportable electronic device based on the status of the package.
 8. Amethod for providing power to a portable electronic device with a solarpower package, the method comprising: deriving solar power with thesolar power package; determining that the solar power package is coupledto the portable electronic device in a plug-and-play fashion; adjustingthe amount of power provided by the solar power package to the portableelectronic device based on attributes of the portable electronic device;and providing the derived solar power to the portable electronic devicein response to determining that the solar power package is coupled tothe portable electronic device.
 9. The method of claim 8, wherein thedetermining further comprises detecting that the derived solar power isappropriate for the portable electronic device.
 10. The method of claim8, wherein the providing the derived solar power comprises: charging abattery of the portable electronic device with the derived solar power.11. The method of claim 8, further comprising storing the derived solarpower in an accessory battery of the solar power package, wherein theproviding the derived solar power comprises providing the derived solarpower stored in the accessory battery.
 12. The method of claim 8,further comprising: determining that the solar power package is notcoupled to the portable electronic device; and storing the derived solarpower in an accessory battery of the solar power package in response tothe determining that the solar power package is not coupled to theportable electronic device.
 13. The method of claim 8, wherein the solarpower package is external to the portable electronic device.
 14. Themethod of claim 8, wherein the portable electronic device comprises oneof a media player, a notebook computer, a tablet computer, a cellularphone, an image processing device, and a handheld computing device. 15.A power package for providing solar power to an external device, thepower package comprising: a solar power source operable to derive solarpower from solar energy; and an auxiliary battery operable to: becharged with the derived solar power, wherein the amount of derivedsolar power provided to the auxiliary battery is adjusted based onattributes of the auxiliary battery; and provide the derived solar powerto the external device in response to the external device being coupledto the power package in a plug-and-play fashion.
 16. The power packageof claim 15, wherein the auxiliary battery is further operable toprovide the derived solar power to the external device in aplug-and-play fashion.
 17. The power package of claim 15, wherein: theauxiliary battery is further operable to provide the derived solar powerin response to the external device selecting the power package from atleast two power sources; and the at least two power sources comprise atleast one power source that provides power via a network connection, auniversal serial bus, a Firewire connection, and a telephone line. 18.The power package of claim 15, wherein the auxiliary battery is furtheroperable to charge an external battery of the external device with thederived solar power.
 19. The power package of claim 15, wherein thepower package is portable.
 20. The power package of claim 15, whereinthe plug-and-play fashion comprises: automatically detecting that thepower package is coupled to the external device; and determining thatthe derived solar power is appropriate for use in the external device.21. The power package of claim 15, wherein the auxiliary battery isfurther operable to concurrently: be charged with a first portion of thederived solar power; and provide a second portion of the derived solarpower to the external device.